I've seen more written on the back of an alphabet book for children. And I know it's a beaten question but when are we ever going to get anything about the Charc? It's been almost a year since you announced it was getting added to the game but we haven't got so much as a Dossier let alone any news on if it's even currently being developed.
So here is all the information I have gathered about the taming mechanics for the Fjordhawk that are noteworthy. Taming % raises if you are not mounted. You can still kill things with a tame but you must be not mounted before the hawk starts feeding. If the fjordhawk is following you while you are on foot if you get on a tame the Hawk will fly away in a random direction until out of render distance.
It seems to only raise % when you are not on a mount, but you can still kill things with your dino. So when you see it landing and walking to the corpse hop off your mount and get back on when it flies up.